Slither serves up a bloody good time indeed. Knowing nothing about the movie going in, I initially thought this was going to be a somewhat disappointing horror film. It didn't take long, though, for me to figure out that what we have here is a real gem of horror comedy.

The secret to its comedic success is the fact that, instead of going over the top for laughs, the characters pretty much play it straight throughout. This thing is just full of terrific one-liners, not to mention subtle in-jokes that extend even beyond the horror genre. There is also plenty of blood and guts for gorehounds to enjoy. This is just one of those films that actually manages to balance that fine line between horror and comedy almost perfectly.

The basic storyline isn't anything new. A meteorite crashes to Earth, unleashing a malevolent lifeform that gets right to work taking over the bodies of the locals and turning them into zombies, leaving a handful of main characters running around and fighting to survive. And, of course, there's also a sort of romantic thing between the leading man and lady.

Wheelsy was a nice, quite, Southern town until this unexpected alien life form dug its way from the chest to the head of Grant Grant (yep, he has the same first and last names), played by Michael Rooker. Grant's a really annoying dude before he turns into a meat-devouring zombie, and you spend the first part of the film wondering why as pretty a young lady as Starla (Elizabeth Banks) ever married him. She's really committed to those wedding vows, but Grant isn't -- not anymore, at least. Soon a whole army of big, nasty, zombifying worms are unleashed to crawl down the throats of anyone and everyone in the local area. These new zombies are not mindless, though -- in fact, they all share Grant's mind.

Grant himself undergoes some rather dramatic physical changes as the story progresses. There are basically three stages in the process: 1) leper, 2) squid, 3) Jabba the Hutt. As Grant grows, his opposition shrinks -- eventually, there is less than a handful of individuals left to try and destroy him. This includes local top cop Bill Pardy (Nathan Fillion), who has carried a torch for Starla since they were kids. The whole story gets pretty ridiculous by the end, but you won't care because it's all so dadburned funny.

I give Fillion tons of credit for his performance. Besides delivering some of the funniest lines, he injects the seriousness required to counterbalance the humor almost perfectly. Without him, I don't think this film succeeds at all as a well-balanced horror comedy. My favorite character by far, though, is Jack MacReady (Gregg Henry), the foul-mouthed mayor whose constant, profanity-laced grumbling never failed to make me laugh.

With so many badly written, unfunny horror comedies out there, it's refreshing to see something new come along and show just how effectively these two different genres can work together. Writer-director James Gunn delivers big-time with Slither: hilarious dialogue, a veritable bounty of blood and guts, and even a tribute of sorts to many a classic horror film of the past. I enjoyed the heck out of this movie.